I. Technological Evolution
glass waste
Glass packaging waste is often mixed with other packaging waste and household garbage. Traditional sorting mainly relies on manual selection, which is labor-intensive and inefficient.
Early, gravity sorting was mainly used. Air separation equipment was used to initially separate low-density materials from high-density materials, and then vibrating screens were used for further sorting of high-density glass and metal.
Modern glass sorting technology has evolved to a stage where multiple high-tech methods coexist, including optical sorting, X-ray fluorescence sorting, laser scanning, and robotic intelligent sorting.
II. Technical Principles Of Glass Waste Sorting
1. In optical sorting technology, identification and sorting are performed based on multiple characteristics such as color and brightness, material size, and material shape.
2. Laser scanning technology uses a more refined method. Laser scanning acquires glass point cloud data, processes the raw point cloud data into slice data, and compresses it. Least squares is used to control point cloud data errors.
3. Image thresholding segmentation method: Foreground and background segmentation of the image is completed by measuring the difference between targets. A quadtree method is used to decompose the foreground image containing the target. 4. X-ray fluorescence (XRF) technology sorts glass by identifying highly precise chemical compositions of the materials. It can identify and sort lead-containing crystals, glass ceramics, copper, tungsten, aluminum, and other metals, as well as toxic elements such as lead, bromine, tin, and antimony.
III. Process Flow
1. Feed Metering: A vibrating feeder evenly feeds the material onto a metering conveyor belt, transporting whole bottles and broken glass to a cross-feeder and a bar screen.
2. Screening and Impurity Removal: The cross-feeder evenly conveys the material to the bar screen, which separates whole pieces from flakes. A pneumatic separator blows out and removes lightweight organic matter from the broken glass.
3. Grading and Crushing: The separated whole pieces are crushed in two stages. The first stage, a double-roll crusher, crushes the bottom of the glass bottles. The uncrushed whole pieces are then conveyed to a second double-roll crusher for further crushing.
4. Coarse Material Sorting: Eddy current separators are used to remove non-ferrous metals, performing three-stage screening at 1-3mm, 3-8mm, and 8-50mm sizes. Materials with particle sizes of 0-8mm are then sent to the fine material sorting system.
IV. Technical Advantages Of Glass Waste Sorting
Multiple Benefits of High Efficiency, Precision, and Economy
1. High-Efficiency Processing Capacity: The X-STREAM-G large-volume glass sorting and separation system can sort 5, 10, or 20 tons of waste per hour, accurately analyzing both wet and dry glass fragments.
2. Intelligent Classification – Waterless Cleaning – Photoelectric Sorting – High-Voltage Electrostatic Sorting – Eddy Current Sorting. Composite Equipment achieves a recovery efficiency of 40 tons/hour, achieving a 99% comprehensive recovery rate for all resources in waste glass.
3. High-Precision Sorting: The optimized waste glass target sorting method based on laser scanning achieves a sorting time of less than 1.5 seconds, with sorting results highly consistent with actual results.
4. Significant Economic Benefits: Recycling glass can save up to 30% of energy, reduce air pollution by 20%, and reduce mining waste gas emissions by 80%.
5. Environmentally Friendly: The composite sorting device produces low waste during production, and the waste is centrally controlled after being drawn in by a negative pressure system, making it environmentally friendly.
From Morgensen’s MSort series optical sorters in Germany to TOMRA’s AUTOSORT COLOR sorting equipment in the United States, and to China’s independently developed intelligent waste glass robotic sorting system, glass sorting technology is constantly innovating and breaking through globally.
When every piece of broken glass can find its proper place through high-tech sorting, we are one step closer to the goal of a resource-recycling society.